scholarly journals Identification of Inhibitors to Trypanosoma cruzi Sirtuins Based on Compounds Developed to Human Enzymes

2020 ◽  
Vol 21 (10) ◽  
pp. 3659
Author(s):  
Tanira Matutino Bastos ◽  
Milena Botelho Pereira Soares ◽  
Caio Haddad Franco ◽  
Laura Alcântara ◽  
Lorenzo Antonini ◽  
...  

Chagas disease is an illness caused by the protozoan parasite Trypanosoma cruzi, affecting more than 7 million people in the world. Benznidazole and nifurtimox are the only drugs available for treatment and in addition to causing several side effects, are only satisfactory in the acute phase of the disease. Sirtuins are NAD+-dependent deacetylases involved in several biological processes, which have become drug target candidates in various disease settings. T. cruzi presents two sirtuins, one cytosolic (TcSir2rp1) and the latter mitochondrial (TcSir2rp3). Here, we characterized the effects of human sirtuin inhibitors against T. cruzi sirtuins as an initial approach to develop specific parasite inhibitors. We found that, of 33 compounds tested, two inhibited TcSir2rp1 (15 and 17), while other five inhibited TcSir2rp3 (8, 12, 13, 30, and 32), indicating that specific inhibitors can be devised for each one of the enzymes. Furthermore, all inhibiting compounds prevented parasite proliferation in cultured mammalian cells. When combining the most effective inhibitors with benznidazole at least two compounds, 17 and 32, demonstrated synergistic effects. Altogether, these results support the importance of exploring T. cruzi sirtuins as drug targets and provide key elements to develop specific inhibitors for these enzymes as potential targets for Chagas disease treatment.

2005 ◽  
Vol 49 (8) ◽  
pp. 3234-3238 ◽  
Author(s):  
Olga Senkovich ◽  
Vandanajay Bhatia ◽  
Nisha Garg ◽  
Debasish Chattopadhyay

ABSTRACT Trypanosoma cruzi, a protozoan parasite, is the causative agent for Chagas' disease, which poses serious public health problem in Latin America. The two drugs available for the treatment of this disease are effective only against recent infections and are toxic. Dihydrofolate reductase (DHFR) has a proven track record as a drug target. The lipophilic antifolate trimetrexate (TMQ), which is an FDA-approved drug for the treatment of Pneumocystis carinii infection in AIDS patients, is a potent inhibitor of T. cruzi DHFR activity, with an inhibitory constant of 6.6 nM. The compound is also highly effective in killing T. cruzi parasites. The 50 and 90% lethal dose values against the trypomastigote are 19 and 36 nM, and the corresponding values for the amastigote form are 26 and 72 nM, respectively. However, as TMQ is also a good inhibitor of human DHFR, further improvement of the selectivity of this drug would be preferable. Identification of a novel antifolate selective against T. cruzi would open up new therapeutic avenues for treatment of Chagas' disease.


2020 ◽  
Vol 367 (23) ◽  
Author(s):  
Edward A Valera-Vera ◽  
Chantal Reigada ◽  
Melisa Sayé ◽  
Fabio A Digirolamo ◽  
Facundo Galceran ◽  
...  

ABSTRACT Trypanosoma cruzi is the causative agent of Chagas disease. There are only two approved treatments, both of them unsuitable for the chronic phase, therefore the development of new drugs is a priority. Trypanosoma cruzi arginine kinase (TcAK) is a promising drug target since it is absent in humans and it is involved in cellular stress responses. In a previous study, possible TcAK inhibitors were identified through computer simulations resulting the best compounds capsaicin and cyanidin derivatives. Here, we evaluate the effect of capsaicin on TcAK activity and its trypanocidal effect. Although capsaicin produced a weak enzyme inhibition, it had a strong trypanocidal effect on epimastigotes and trypomastigotes (IC50 = 6.26 µM and 0.26 µM, respectively) being 20-fold more active on trypomastigotes than mammalian cells. Capsaicin was also active on the intracellular cycle reducing by half the burst of trypomastigotes at approximately 2 µM. Considering the difference between the concentrations at which parasite death and TcAK inhibition occur, other possible targets were predicted. Capsaicin is a selective trypanocidal agent active in nanomolar concentrations, with an IC50 57-fold lower than benznidazole, the drug currently used for treating Chagas disease.


2011 ◽  
Vol 79 (10) ◽  
pp. 4081-4087 ◽  
Author(s):  
Craig Weinkauf ◽  
Ryan Salvador ◽  
Mercio PereiraPerrin

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.


PEDIATRICS ◽  
1983 ◽  
Vol 71 (6) ◽  
pp. 985-985
Author(s):  
RIF S. EL-MALLAKH

To the Editor.— Mitochondrial failure, manifest by changes in mitochondrial enzyme activity1-3 and morphology,4-5 is central to Reye's syndrome (RS).6 Although it has been variously hypothesized that the mitochondrial changes are secondary to an exogenous toxin,7-12 or an intrinsic mitochondrial defect,6 the actual cause remains obscure. Electron microscopic studies have shown sweelling and loss of cristate in mitochondria of patients with RS. It is interesting that very similar changes occur in Trypanosoma cruzi.13-16 T cruzi is an extracellular/intracellular protozoan parasite which causes Chagas' disease.17


PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e32918 ◽  
Author(s):  
Michelle Oppenheimer ◽  
Ana Lisa Valenciano ◽  
Karina Kizjakina ◽  
Jun Qi ◽  
Pablo Sobrado

2015 ◽  
Vol 59 (8) ◽  
pp. 4669-4679 ◽  
Author(s):  
Nilmar Silvio Moretti ◽  
Leonardo da Silva Augusto ◽  
Tatiana Mordente Clemente ◽  
Raysa Paes Pinto Antunes ◽  
Nobuko Yoshida ◽  
...  

ABSTRACTAcetylation of lysine is a major posttranslational modification of proteins and is catalyzed by lysine acetyltransferases, while lysine deacetylases remove acetyl groups. Among the deacetylases, the sirtuins are NAD+-dependent enzymes, which modulate gene silencing, DNA damage repair, and several metabolic processes. As sirtuin-specific inhibitors have been proposed as drugs for inhibiting the proliferation of tumor cells, in this study, we investigated the role of these inhibitors in the growth and differentiation ofTrypanosoma cruzi, the agent of Chagas disease. We found that the use of salermide during parasite infection prevented growth and initial multiplication after mammalian cell invasion byT. cruziat concentrations that did not affect host cell viability. In addition,in vivoinfection was partially controlled upon administration of salermide. There are two sirtuins inT. cruzi, TcSir2rp1 and TcSir2rp3. By using specific antibodies and cell lines overexpressing the tagged versions of these enzymes, we found that TcSir2rp1 is localized in the cytosol and TcSir2rp3 in the mitochondrion. TcSir2rp1 overexpression acts to impair parasite growth and differentiation, whereas the wild-type version of TcSir2rp3 and not an enzyme mutated in the active site improves both. The effects observed with TcSir2rp3 were fully reverted by adding salermide, which inhibited TcSir2rp3 expressed inEscherichia coliwith a 50% inhibitory concentration (IC50) ± standard error of 1 ± 0.5 μM. We concluded that sirtuin inhibitors targeting TcSir2rp3 could be used in Chagas disease chemotherapy.


2018 ◽  
Vol 113 (3) ◽  
pp. 153-160 ◽  
Author(s):  
Elena Aguilera ◽  
Javier Varela ◽  
Elva Serna ◽  
Susana Torres ◽  
Gloria Yaluff ◽  
...  

2020 ◽  
Author(s):  
Edward A. Valera-Vera ◽  
Chantal Reigada ◽  
Melisa Sayé ◽  
Fabio A. Digirolamo ◽  
Mariana R. Miranda ◽  
...  

ABSTRACTTrypanosoma cruzi is the causative agent of Chagas disease, considered within the list of twenty neglected diseases according to the World Health Organization. There are only two therapeutic drugs for Chagas disease, both of them unsuitable for the chronic phase, therefore the development of new drugs is a priority.T. cruzi arginine kinase (TcAK) is a promising drug target since it is absent in humans and it is involved in cellular stress responses. In a previous study from our laboratory, possible TcAK inhibitors were identified through computer simulations, resulting in the best-scoring compounds cyanidin derivatives and capsaicin. Considering these results, in this work we evaluate the effect of capsaicin on TcAK activity and its trypanocidal effect. Although capsaicin produced a weak inhibition on the recombinant TcAK activity (IC50 ≈ 800 µM), it had a strong trypanocidal effect on epimastigotes and trypomastigotes (IC50 = 6.26 µM and 0.26 µM, respectively) being 20-fold more active on trypomastigotes than mammalian cells. Epimastigotes that overexpress TcAK were 37% more resistant to capsaicin than wild type parasites, suggesting that trypanocidal activity could be due, in part, to the enzyme inhibition. However, the difference between the concentrations at which the enzyme is inhibited and the parasite death is caused implies the presence of other targets. In this sense, the prohibitin-2 and calmodulin were identified as other possible capsaicin targets. Capsaicin is a strong and selective trypanocidal agent active in nanomolar concentrations, with an IC50 57-fold lower than benznidazole, the drug currently used for treating Chagas disease.


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